My ex and I broke up about a week ago and since then we ran into each other twice and he made conversation with me, he smiles at me and gets glances of me, he looks very happy to see me and it seems like he wants me to stay longer but doesn't know how to say it directly. He texted me once and we had a brief talk about what happened between us and how we've been in general. He also sent me a song saying he missed me. Apart from this, we don't text. He seems to truly miss me and he seems to be happy when we talk but he hasn't texted me? He has other things going on so I'm sure he just needs time to think about things but I'm not sure.. What can I do?